What do you think of this repair history?

[Birdibus]

This is a repair history for a 74 bus. I would like some honest opinions, particularly about the frequency of head replacements. Sorry, I couldn't figure out how to post it here.

[albumimg]74[/albumimg]

[kool aid]

Well, mechanically, Im a novice but I have to wonder about the quality of parts being used. It seems this particular engine is going through a lot of vital parts. Are these parts new, used, remanufactured?

[Sluggo]

This is a repair history for a 74 bus. I would like some honest opinions, particularly about the frequency of head replacements. Sorry, I couldn't figure out how to post it here.

[albumimg]74[/albumimg]

I did it for you. On the image page look at the box labeled "bbcode" Copy & paste the short code in your message. It then puts a thumbnail in the message which you can then click on for the full image.

[Amskeptic]

This is a repair history for a 74 bus. I would like some honest opinions, particularly about the frequency of head replacements.

Not too bad until the last interval. You can safely assume that the heads will get "sore" from each rebuild. The next time, get it done right. New guides mandatory so you can really cut the seats acurately concentric. I recommend phosphur bronze guides. Cut the exhaust valve seats to no more than 2.5mm wide or you will run the risk of premature sealing failure due to trapped carbon particles.
Colin

[Birdibus]

Colin, thanks for the suggestions, even though I don't understand a lot of what you said. I need to find somewhere an explanation of basic engine rebuilds and more intensive rebuilds, in layman's terms.

When I went through all those service receipts, I was surprised to find two rebuilds I had no memory of. I had the jobs done by 3 different mechanics, the last couple of them by my regular guy. It was disappointing to realize how few miles I actually put on some of them. I thought type4 motors were more durable, so I'm thinking something has been overlooked.

Sorry I can't give more details about new/used/remanufactured. I have a hard time reading some of the receipts, but at least I've learned what a push rod tube is.

You probably noticed an 8 year gap in the record. The bus sat under a carport for years waiting for the smog laws to change and money to be saved to pay the mechanic.

I wish I had found my internet VW friends before the last big job. Sigh, next time. I guess I will be the person asking for good rebuild shops in the forums one of these days.

What is a 'ring job"? My mechanic tells me it needs to be done next time.

[Birdibus]

OK. I pulled out my yellowed, oil stained old copy of Muir's book (which ends at model year 1973) and searched for engine diagrams. I realize now I don't know exactly what the "heads" are. They are part of the valve assembly, right? But exactly which parts? So grinding valves and replacing heads go together. Anything else?

Now I see the "rings" are attched to the piston, and replacing them is a "bottomend" procedure. The case needs to be split for this, right? Once open, what other inspection, maintaince or replacements need to be done?

Where is the camshaft in relation to the main bearing assembly? Above? Below?

I don't know the basics of Automotive 1A, so with a little help from a friend and the bits and pieces of engine drawings I found in Muir's book, I now have a little better understanding of how engines work. I was upset with how there was no drawing of "the big picture", but we finally figured out how the various drawings fit together, except for the camshaft location.

I remember my frustration when I used this book long ago to tune up my Bug. I could do some basic procedures, but never really understood the engine, which was frustrating to me. I felt I was too much of an idiot to understand a book for 'compleat' idiots! Ha ha. It's ok, I feel better now.

[77_Bus_Girl]

I hear your pain. I suffer from a similar situation - I "get" how an engine works on a very basic level, but don't know what all the bits are called or exactly what they do. I too have dreamed for a basic drawing of the engine (from multiple views, and heaven forbid a cross section!) with little arrows pointing to all the bits. Then there would be a short explanation (written in a language I can understand) of that they all did and what happens when they are malfunctioning.

Ahh. to dream.

[Elwood]

Hi Birdibus and 77-Bus-Girl, this is Barb aka Elwood,

What a kick to read your post, I understand and concur with wanting and needing more to understand. I have the early engine and have been told it still works the same, just on its side. Well ok, but show me the visual.

I ask Colin to include in his book a glossary to explain all the terminoligy used so commenly in posts and books. Really hope it happens here on the IAC .

I did rebuild my 1600 out of dire straights over 10yrs ago and used the Haynes manual because of the pictures. The Muir is a easy read and I love it but we need a inbetween -Bently and Muir- Colin and others can you deliver?

BTW ~~~ because we can on this site ~~~ I love your chic input and the camp receipts thread, I will add to it in future. And Birdi did you receive your shipment?

You gals have the skills with picts and posting I hope to learn ~~ someday. Ha just saw what that emoticon means -

[VWBusrepairman]

I know what the engine parts are called, can build long-lasting engines, maintain my own engine, and comprehend most of Colin's vocabulary, but time is what I am lacking these days, unfortunately.

This is a good place to learn!

[77_Bus_Girl]

BTW ~~~ because we can on this site ~~~ I love your chic input and the camp receipts thread, I will add to it in future. And Birdi did you receive your shipment?
You gals have the skills with picts and posting I hope to learn ~~ someday. Ha just saw what that emoticon means -

It's great to see other women in here with the automotive know-how and desire! (my computer-nerd background permits me to post pictures, but not know what they are!) I'm fairly new to it all - I've had Jurgen for only 4 years now, but I know so much more than I did when I started. (thanks in a large part to sites like this!) It's great that we all have a place we can ask questions and not be made to feel stupid for not knowing what a Bowden tube is (although now I know it has something to do with a clutch!)

I hope more people add to the recipe list - I know it's kinda girly but everyone likes good food!

[Birdibus]

Hi ladies~ Yes, we need to learn more about our cars so we can take care of them better. Sounds like I need another book or two. I must also go and find the camp cooking topic. Barb, the rendevous is Thurs. Did you find yourself under that thunderstorm on Monday?

Barb, it may say geek, but I think it's a rasta.

So again, what exactly are the heads? What is involved in replacing them? Is this usually a new part, or are they sometimes refurbished? What makes them crack?

Also, what is a cylinder? Is it a removable sleeve inside the case that a piston travels through?

[Amskeptic]

we need to learn more about our cars so we can take care of them better.
A) what exactly are the heads?
B) What is involved in replacing them?
C) Is this usually a new part, or are they sometimes refurbished?
D) What makes them crack?
E) Also, what is a cylinder?

That is true for all of us at all times.

A) Heads are like the business end of a cannon, where you light the fuse to ignite the dynamite. The piston would be the cannonball. Heads are where you put in the spark plugs which ignite the fuel/air, adjust your valves which let in the fuel/air and let out the exhaust, and they are where the pushrod tubes go from the crankcase in the middle of the engine. They cap two cylinders each, so your left head caps # 3 and 4, and the right head caps cylinders # 1 and 2.

B) Replacing them is straighforward with a VW engine. Remove the junk attached to intake/exhaust manifolds and then remove the intake and exhaust manifolds themselves, the tins covering the engine, then you can remove the rocker arms and pushrods (they open the valves which are stuck in the heads) and unscrew the cylinder head nuts and pull them off.
Use a manual, this is just the overview.

C) If your heads are in good shape, no cracks and no horrible overheat history, try to recondition them. You can get exchange heads that have already been machined and inspected, this is quicker than waiting for yours if time is important. New heads are available, but the Spanish AMCs for the Type 4, you should dump the valves and springs and retainers from them and have your own high quality parts rounded up and installed instead.

D) Heat, too much, due to lean mixtures - vacuum leaks etc.

E) Cylinders are cast iron "sides of the cannon" to guide the piston cannonballs as they repeat the intake/compression/power/exhaust strokes. Go look under your engine up inside those lower tins. Shiny fins maybe oily or merely grey at center, crankcase. Rusty cast iron fins are the cylinders. Grey fins out near the edges of the engine where the exhaust pipes connect, cylinder heads.

I hope to post some early pages from the book about this stuff. . . soon.
Colin

[spiffy]

To give you some sort of feed back on the head maintenance issue, my original engine lasted from 1978-1992 and tacked on 130K miles....AHHH original parts!!! A full rebuild in 1992 with AMC (head maker in Spain) lasted 55K miles but the PO (previous owner) beat the hell out of the motor and two (# 3 and #4) intake valve seats were beat into the head. So, my bottom end (the crankshaft, camshaft and associated bearings and the case) should live another 50K at least....lets see how long these new AMC heads last. When this engine gives it up, a Camper Special is going to be the way I go.